Now this is my current hex file, but what if I want to upload another code? Do I have to change this parameter every time?

No. In the setup for external tools there are meta-variables available to insert into the parameter textbox. Click the arrow to the right of it to see what is available. On the pad, not on the PC, right now so can't be more specific.

Perhaps take a look at the Studio help?

As of January 15, 2018, Site fix-up work has begun! Now do your part and report any bugs or deficiencies here.

No guarantees, but if we don't report problems they won't get much of a chance to be fixed! Details/discussions at link given just above.

"Some questions have no answers."[C Baird] "There comes a point where the spoon-feeding has to stop and the independent thinking has to start." [C Lawson] "There are always ways to disagree, without being disagreeable."[E Weddington] "Words represent concepts. Use the wrong words, communicate the wrong concept." [J Morin] "Persistence only goes so far if you set yourself up for failure." [Kartman]

As of January 15, 2018, Site fix-up work has begun! Now do your part and report any bugs or deficiencies here.

No guarantees, but if we don't report problems they won't get much of a chance to be fixed! Details/discussions at link given just above.

"Some questions have no answers."[C Baird] "There comes a point where the spoon-feeding has to stop and the independent thinking has to start." [C Lawson] "There are always ways to disagree, without being disagreeable."[E Weddington] "Words represent concepts. Use the wrong words, communicate the wrong concept." [J Morin] "Persistence only goes so far if you set yourself up for failure." [Kartman]

I don't recommend that anyone use spaces in folder/directory or file names. Microsoft people laugh at my concern and say, "but of course you silly user, you can have spaces in filenames. We fixed that back in version XYZ." With MS the fixes that they do work well with the programs that they sell, and not so well on the 99.9% of the programs in general use that they don't sell. And utility programs (regardless of how well written and supported that they are by their communities) tend to be written to be used by people who learned to program back in the 1960s and 1970s, and write code that has general conventions in their operation that date back to that era. Things like being unable to support file names/directory names that have spaces in them. Or inappropriate case sensitivity. Or a thousand other stupid things.

So just pretend that you are back in 1972 and rename your directory/file names with arbitrary letter combinations (like e:\PFE\ for e:\Program File Examples\) and chances are good that things will start working better.

When Studio WhateverNumber starts loading in the same time that it takes the Arduino IDE to load, then I will start to be convinced that it is actually as good as the Arduino IDE. But that's never going to happen. AVR Studio is useful when (for whatever reason) you absolutely have to work with a specific AVR part, but I believe that the concept of choosing the CPU device to meet the needs of the application is out-of-date. Now one should chose the smallest Arduino selection that can hold your application and buy pre-made inexpensive Chinese clone boards to run the ap on. Since, eBay only inexpensively sells a few Arduino models, this step is quite easy. There's the Mega328p (the UNO/nano), the Mega2560 (the Mega), and the Mega32u4 (the Leonardo), and that's about it.

I do have old clone boards that don't have the CH340 USBserial IC on them. They instead have worthless and expensive FTDI and Prolific ICs mounted. For these I use a ISP programmer (USBASP) that loads a hex file generated by Arduino's SKETCH-Load Compiled Binary. These hex files can be loaded by calling AVRdude from the command line using a batch file.